Exposed Aggregate Concrete: The Complete Guide for 2026

Exposed aggregate concrete generates 8,100 monthly searches — and it's one of the most profitable decorative concrete services a contractor can offer. With prices ranging from $8 to $18 per square foot (vs. $6-10 for plain concrete), the margins are excellent. This guide covers everything: installation methods, aggregate selection, sealing, pricing, and how to build a profitable exposed aggregate business.

What Is Exposed Aggregate Concrete?

Exposed aggregate is a decorative concrete finish where the top layer of cement paste is removed to reveal the stone, gravel, shells, or other decorative materials (aggregate) embedded in the concrete. The result is a textured, visually appealing surface that's naturally slip-resistant and extremely durable.

Unlike stamped concrete that mimics patterns, exposed aggregate showcases real stone — giving it an organic, high-end look that homeowners love. It's been popular in Australia and Europe for decades and is gaining rapid traction in the US market.

Why Contractors Should Offer Exposed Aggregate

• Higher margins: You charge $8-18/sq ft vs. $6-10 for plain concrete — with only marginally higher material costs.
• Natural slip resistance: The textured surface makes it ideal for pool decks, walkways, and driveways — areas where slip-resistance matters and customers will pay premium prices.
• Low maintenance: Sealed exposed aggregate lasts 25-30+ years with minimal upkeep, leading to happy customers and referrals.
• Upsell opportunities: Every plain concrete job is a chance to upsell to exposed aggregate. "For $3 more per square foot, you get this finish instead."
• Differentiation: Most small concrete crews only do flatwork. Offering decorative finishes sets you apart from the "pour and go" competition.

3 Methods for Creating Exposed Aggregate

1. Surface Retarder Method (Most Common)

This is the standard approach used by most contractors. A chemical surface retarder is sprayed or rolled onto freshly placed concrete. The retarder delays the setting of the top 1/8" to 1/4" of cement paste while the concrete below cures normally.

Process:

1. Place and screed the concrete as normal
2. Bull float for a smooth surface
3. Apply surface retarder when the concrete can support foot traffic (typically 4-6 hours depending on conditions)
4. Cover with plastic sheeting to prevent moisture loss
5. Wait 12-24 hours (follow retarder manufacturer's instructions)
6. Pressure wash the uncured surface paste away to expose the aggregate
7. Allow to cure fully, then apply sealer

Pros: Predictable results, works with any concrete mix, widely available products.
Cons: Timing is critical — apply retarder too early and it sinks too deep; too late and it won't penetrate.

2. Seeding Method (Premium Results)

Decorative aggregate (river rock, glass, shells, colored stone) is broadcast onto the surface of freshly placed concrete, then pressed in with a float or roller. This gives you complete control over the appearance since you choose exactly what aggregate shows.

Process:

1. Place concrete and screed to slightly below final grade (about 3/8" low)
2. Spread decorative aggregate evenly across the surface by hand or broadcast spreader
3. Tap/press aggregate into the surface with a magnesium float or roller
4. Continue floating until aggregate is fully embedded but still visible
5. Apply surface retarder, cover, and wash as above

Pros: Complete control over appearance, can use premium aggregates not available in local ready-mix, stunning visual results.
Cons: Higher material cost ($1-4/sq ft for decorative aggregate), more labor-intensive, requires skill to get even distribution.

3. Washing and Brushing Method (Traditional)

The oldest technique — simply washing or brushing away the uncured surface paste before it fully sets. No chemicals required, but timing is everything.

Process:

1. Place, screed, and float concrete
2. Wait until concrete is firm enough to resist deep gouging but soft enough for surface removal (the "thumb test" — you can leave a thumbprint but not sink in)
3. Use a stiff broom and water to brush/wash away surface paste
4. For deeper exposure, use a pressure washer at low setting

Pros: No chemical products needed, lowest cost method.
Cons: Extremely timing-dependent (you have a 30-60 minute window), inconsistent results on large pours, hard to scale.

Choosing the Right Aggregate

The aggregate you use defines the final look. Here's what works best for different applications:

Pro tip: Always do a test panel (2'x2' minimum) for the customer before committing to a full pour. Aggregate color changes when wet vs. dry, and customers need to approve the sealed appearance. A 5-minute test panel prevents a $5,000 dispute.

Sealing Exposed Aggregate (Critical Step)

Sealing is non-negotiable for exposed aggregate. Without sealer, the surface will absorb stains, lose color vibrancy, and the aggregate can loosen over time. Here's what to know:

Sealer Types for Exposed Aggregate

• Acrylic sealer ($0.15-0.30/sq ft): Most common choice. Available in matte, satin, or gloss. Easy to apply, dries fast, enhances color. Reapply every 2-3 years. Good for most residential applications.
• Penetrating sealer ($0.20-0.50/sq ft): Soaks into the concrete without changing appearance. Best for driveways in freeze-thaw climates. Won't peel or flake. Lasts 5-10 years.
• Polyurethane sealer ($0.30-0.60/sq ft): Maximum durability and chemical resistance. Best for commercial or high-traffic areas. Lasts 5+ years but harder to reapply.
• Epoxy sealer ($0.40-0.80/sq ft): Highest gloss and hardness. Can yellow in UV exposure — use only for covered/indoor areas.

Contractor recommendation: For most residential exposed aggregate, use a solvent-based acrylic in a satin finish. It enhances the stone colors without looking "plastic," and reapplication every 2-3 years creates a natural maintenance revenue stream. Charge $1.50-2.50/sq ft for sealing — it's a high-margin add-on.

Pricing Exposed Aggregate Work

Here's a real-world pricing breakdown for a typical 600 sq ft exposed aggregate driveway:

Exposed Aggregate vs. Other Decorative Finishes

Common Mistakes (and How to Avoid Them)

1. Washing too early: If you pressure wash before the concrete has set enough, you'll dislodge aggregate and create craters. Always do the "thumb test" — the surface should resist your thumb with moderate pressure.
2. Washing too late: If you wait too long, the surface paste hardens and won't wash off cleanly. You'll end up with a patchy finish. Surface retarders give you a much wider window — use them.
3. Inconsistent exposure depth: Uneven washing creates a blotchy look. Use a consistent pressure washer distance (12-18 inches) and overlapping passes. Work in sections, not random spraying.
4. Skipping the sealer: Unsealed exposed aggregate absorbs stains (oil, rust, leaves) within months. Always seal, and educate the customer on resealing every 2-3 years.
5. Wrong aggregate size: Aggregate that's too small (under 1/4") creates a sand-paper texture. Too large (over 1") can feel uncomfortable underfoot. The sweet spot for most applications is 3/8" to 3/4".
6. No test panel: Every customer has a different idea of "exposed aggregate." A 2'x2' test panel takes 20 minutes and prevents callbacks.

Building an Exposed Aggregate Business

If you want to specialize in exposed aggregate work, here's the playbook:

Equipment You Need

• Pressure washer (3,000+ PSI): $400-800 for a commercial-grade unit. This is your most important tool — invest in quality.
• Surface retarder: $30-50 per gallon (covers ~200 sq ft). Keep multiple strengths in stock for different exposure depths.
• Sprayer (for retarder): $50-100 pump sprayer. Dedicated — don't use the same sprayer for sealer.
• Sealer sprayer/roller: $50-150 depending on method.
• Sample boards: Make 12"x12" samples of your most popular aggregate options. Show these to customers during estimates. Professional samples close more jobs.

Marketing Exposed Aggregate Services

• Before/after photos: Exposed aggregate photographs beautifully. Build a portfolio — every job is a marketing asset.
• Focus on pool decks and patios: These are the highest-value applications where customers are already spending on landscaping and willing to pay premium prices.
• Offer sealing as a maintenance service: Every exposed aggregate job becomes a recurring customer for resealing every 2-3 years at $1.50-2.50/sq ft. Build a database and send reminders.
• Partner with landscape designers: They specify materials for high-end outdoor projects. Be their go-to concrete contractor.

Frequently Asked Questions

How long does exposed aggregate concrete last?

With proper installation and maintenance (resealing every 2-3 years), exposed aggregate concrete lasts 25-30+ years. Many installations from the 1990s are still in excellent condition.

Is exposed aggregate concrete slippery?

No — exposed aggregate is one of the most slip-resistant concrete finishes available. The protruding stones create natural traction, making it ideal for pool decks, walkways, and driveways. However, avoid high-gloss sealers in wet areas — use matte or satin finish sealers instead.

Can you do exposed aggregate on existing concrete?

Not directly — you can't retroactively expose the aggregate in existing cured concrete. However, you can apply an exposed aggregate concrete overlay (a thin bonded topping with decorative aggregate) over existing slabs. Overlays are typically 3/8" to 3/4" thick and cost $8-15/sq ft installed.

What's the best aggregate for a driveway?

For driveways, use hard, durable aggregate like crushed granite, river rock, or quartz in the 3/8" to 3/4" size range. Avoid soft stones like limestone in high-traffic areas — they can wear smooth over time. Most concrete driveways use local pea gravel or crushed stone from the ready-mix supplier for cost efficiency.

How soon can you drive on exposed aggregate?

Wait a minimum of 7 days before allowing vehicle traffic, and 28 days for full cure. The sealer needs 24-48 hours to cure before any traffic. Rushing this is the fastest way to ruin a beautiful pour.